Diversity of home-field effects among genotypes and difference of relative mixture effect among conditioned soil treatments in a Leymus chinensis litter decomposition experiment

Background and Aims

Ecological effects of biodiversity have been studied for several decades; however, at micro-scales, how genotype identity and richness within a species affect litter decomposition processes remains largely unknown.

Methods

A litter reciprocal incubation experiment of four Leymus chinensis genotypes (litter a ~ d; soil A ~ D) was carried out, including a mixture decomposition on each conditioned soil. Based on litter mass, C, N loss percentages, litter quality, soil functional ability and home-field advantage (HFA) were estimated by a decomposability regression test; and relative mixture effects (RMEs) were estimated by non-additive effect.

Results

(1) Litter mass and C loss percentages were affected by conditioned soil and litter genotype × conditioned soil. The direction and significance of the correlation coefficient between litter mass (C, N) loss percentages and indicators of litter initial properties and soil decomposer community were different among home-field decomposition (in single), away-field decomposition (in single), and mixture decomposition. (2) Significant positive HFAs were found in genotype-a which was characterized as the lowest litter quality and the highest soil functional ability. (3) Significant positive RMEs were found on litter C and N loss percentages in soil-D which was characterized as the highest soil microbial diversity and the lowest soil functional ability.

Conclusion

At a micro-scale, low-quality litter of L. chinensis genotype favors an HFA for single decomposition, while soil with high microbial diversity promotes a positive RME for mixture decomposition, which highlights the ecological importance of spatial distribution of litter.